Rack screen cleaner



W. AL DUNDASET AL N RACK SCREEN CLEANER 'Filed March 5. 1929 sept. 15, 1931.

' Sept. l5, 1931. w. A. DUNDAS ET Al.

RACK SCREEN CLEANER Sept. 15, 1931. w. A. DUNDAS ET AL 1,823,823

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Patented Sept. 15, 1931 l'lhil'li';l STATES WILLIAM A. DUNDAS .AND LLOYD M. JOHNSON, OF'CI-IICAGO, ILLINOIS RACK SCREEN CLEANER Application led March 5, 1929. Serial No. 344,447.

Our invention relates to improvements in screens forV sewage and the vlike and has for one object to provide in combination with a trash screen means forautomatically clean- 5 ing the'soreen Vand for discharging the refuse material so cleaned from the screen. A nother objectof the invention is to provide a-.trash rack which will be flexible though positive: in opera-tion, exert to some extent 10 a digging V`action which will be strong, durable and not subject to breakage and obstine' tion byfpresence` of large ypieces of trash. Other object-s will appear from time to time throughout the specification and claims.

Our invention is illustrated more or less diagramm-atically in the accompanying drawings, wherei-n- Figure l is a side elevation inpartsection ofthe device;

Figure/2` isa plan view Figure 3 isavie'w of the counterweight;

Figure is a side elevation showing the rake at the Vupper end of its excursion -about to be tripped;

Figure shows the rake in section after it has been tripped;

Figure is a detail plan view of part of the 'rake Figure 7 is a section along 30 ofFigure 4; y

Figure 8 isa section along the line 8-8 of Figure l.

Like parts are indicated 'by Ylike characters throughoutthe specification and drawings.

Sib A is the channel or passage through which dirt or trash laden water-or sewage travels in the direction of the arrows. A1 isk an inclined'trash screen or grid extending vertically across the channel andfterminating at U its upper end in a continuous lined apron A2 which discharges into the trough A3 at the bottom of which isa conveyor belt A4 adapted to carry olf them-aterial which is discharged into the trough. A5 is a motor l5 and Aca reduction gear-by which the motor drives `the conveyor belt. A4.

B is an angle track, there beingone at each side ofV the channel mounted in the side walls thereof in front of the grid and parallel CJ'therewith; Associatedlwith'each track is a the line 7 7 cover plate B1. These tracks are rigidly mounted on the wall, there being packing members B2 between them and the wall. Traveling on each of these tracks and held in place by the-cover plate 'is a carriage B3.. The carriages are identical and a description of one will sufce `for both. The carriage comprises a cradle ymember forwardly extended between its ends as at B12 and at either end is a fiangedroller-B13 so ythat thef6 carriage does not rotate. Extending across between the two carriages isa rake vbeam B4. This carriage and rakebeam combination ,is free to travel along the tracksgoing down by gravity and being drawnup by cables B5 extending parallel with the tracks yand wound about the drums Bfs von @drive shafts B7 which are driven in turn through a gear box B8, gear reduction boxes B9 fromthe motor B10. Associated with the motor .Bmnm is a solenoid brake B11 to controlthe operation of the shaft driven thereby.

Projecting downwardly from the rake beam B4 are pivotlugs C carrying pivot pins C1 in pivotal engagement with hinge -lplates 75 C2 on a rake plateGS. This .rake plate C3 carries a pluralityof downwardly extending stilf spring arms C4 which arms carryscraper plates C5 which terminate in .teeth C0, there being one tooth adapted ,to penetrate between each pair of screen bars. These spring arms C4 terminate in coil spring C7 woundabouta bar CS which is held in position on the plate C3 by U-clamps C9. Projecting forwardly from the plate C3 at both ends are counter?l weight levers C10 tending to hold the rakes and cleaning teeth Vdown in the position shown in Figure 4to work upon the screen butgiving a considerable measure of flexibility sol that in the event that the vdevice shouldencounter anything which could not move, the rake would give and slide over and would not break.

At the upper end of the excursion ofthe rake above the trough A3 is a trip trackl D adapted to be engaged bya roller D1 on a lever D2 associated with the rakeso that as the carriage movesfrom the position shown in'Figure' 4to the uppermost'part shown in Figure 5, this lever. is rotated to swing the plate C3 into the position shown in Figure 5 so that the dog D3 on the arm D4 extending from the plate will engage the pivoted pawl or latch D5 to lock the rake in the inoperative position. As the rake travels from the working position shown in Figure 4 to the inoperative position shown in Figure 5, the scraper blade DG mounted on supporting springs D7 scrapes the underside of the blade and discharges any material which may be on it into the trough A4. C15 is a downwardly projecting stop in the lug C adapted to engage the swivel D10 of the lever D2 in the position shown in Figure 4. As soon as the rake is tripped into the position shown in Figure 5, the mechanism is reversed and the carriage descends by gravity to its lowermost excursion as shown in Figure l. At this time a tension is exerted by the chain E which springs the latch D5 and permits the counvterweights to rotate the rake into the position shown at the bottom on Figure l causing a slight digging action at the bottom of its travel to insure digging out of any refuse which may be piled up at the bottom of the screen. YThe chain E is operated by a counterweight El which is suspended by the chain as it passes over a pulley E3. The chain E4, adjustable in length is provided to limit the distance to which the counterweight may descend.

In operation the electric motor is controlled to cause the rake to have up and down or back and forth movement along the track. As it goes down it is retracted from and out of contact with the screen so that there is no tendency for refuse to be pushed down along the screen. At the end of its downward excursion the rake digs in to any refuse which may be piled in at the bottom when it is released by tlie latch which is a result of its downward stroke and it then comes up scraping any refuse found upon the screen which would not pass through upward and discharging it into the trough. When the rake is tripped any material which may have been deposited on the working face of the rake is scraped oii' andthe rake therefore returns ready for another working stroke in a cleaned condition.

We claim:

1. In combination with a rack screen, a track parallel therewith, a carriage adapted to run along the track, a rake pivoted on the carriage, automatic means for holding the rake in engagement with the screen, means operative only at the upper end of the carriage excursion for moving the rake out of engagement with the screen, means operative only at the lower end of the carriage excursion tor automatically throwing the rake into engage-ment with the screen, the meansV Jfor throwing the rake into engagement with the screen comprising a latch associated with thecarriage and a limiting member adapted to trip the latch when the carriage reaches the lower end ot its excursion.

2. In combination with a rack screen, a track parallel therewith, a carriage adapted to run along the track, a rake pivoted on the carriage, automatic means for holding the rake in engagement with the screen, means operative only at the upper end of the carriage excursion tor moving the rake out of engagement with the screen, means operative only at the lower end of the carriage eXcursion for automatically throwing the rake into engagement with the screen, the means for the throwing the rake out of contact with the screen comprising a cam, a lever associated with the rake adapted to engage the cam toward the upper end of the rake excursion and a latch adapted to hold the rake in the disengaged position.

3. The combination with an inclined trash screen et a rake, means for moving it upwardly therealong to scrape material toward the upper end thereof, an apron in continuation otthe screen and a trough into which the rake may discharge material from the screen and across the apron, means for giving the rake a reciprocating movement, the eX- cursion ot which extends throughout the entire length of the screen, means for tripping the rake to cause it to return free of engagement with the screen, and means for latching the rake in the inoperative position prior to its tree return. i

t. The combination with an inclined trash screen of a rake, means for moving it upwardly therealong to scrape material toward the upper end thereof, an apron in continuation ot the screen and a trough into which the rake may discharge material from the screen and across the apron, means for giving the rake a reciprocating movement, the excursion of which extends throughout the entire length of the screen, means for tripping the rake to cause it to return tree of engagement with the screen, and means for latching the rake in the inoperative position prior to its free return, and means associated with the latching means Jfor cleaning the rake.

5. In combination with a rack screen, a track parallel therewith, a carriage adapted to run along the track, means for moving said carriage, a rake pivoted on the carriage, automatic means for holding the rake in e-ngagement with the screen, separate means additional to the track and to the carriage moving means operative only at the upper end of the carriage excursion for moving the rake out ot engagement with the screen, means 0perative only near the lower end of the carriage excursion while the carriage is moving downwardly Jfor automatically throwing the rake into engagement with the screen.

6. In combination with a rack screen, a track, parallel therewith, a carriage and means for reciprocating it along the track, a

rake mounted on the carriage and movable thereon into and out of operative relation With the screen, separate means additional to the track and to the carriage moving means rendered operative by the downward movenient of the carriage for moving the rake on the carriage into operative relation With the screen at the lower end of the carriage eX- cursion and separate means additional to the track and to the carriage moving means for moving the rake on the carriage out of operative relation with the screen at the upper end of its excursion and means for holding the rake in Whichever position it has been placed during its movement from one end to the other of its excursion, said means being additional to the track and to the carriage moving means.

Signed at Chicago, county of Cook and State of Illinois, this 28th day of February,

WILLIAM A. DUNDAS. LLOYD M. JOHNSON. 

